Stoker apparatus



Patented June 10, 1941 STOKER APPARATUS Donald J. Mosshart, Springfield, Pa., assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application January 12, 1939, Serial No. 250,493

14 Claims.

The invention relates to combustion apparatus, and particularly to stokers having one or more substantially horizontally arranged retorts, with fuel-supporting surfaces disposed laterally of the latter, and it has for an object to provide apparatus of this character having improved means for moving fuel and/or solid products of combustion progressively.

Another object of the invention is the provision of improved means for positively feeding fuel along laterally-extending grates from the retorts towards the side walls of the furnace.

Yet another object of the invention is the pro vision of a retort defined by a horizontal fuel supporting surface and longitudinally reciprocable tuyere members disposed at the sides of the supporting surface.

A further object of the invention is the provision of a stoker in which the fuel is fed laterally thereof, together with novel means for automatically conveying the ash therefrom to the front of the furnace for convenient disposal.

A further object of the invention is the provision of a stoker having means for positively feeding fuel laterally thereof and means for conveying the ash therefrom to the front of the furnace together with a novel connection of both of said means with the main ram for feeding fuel to the stoker.

These and other objects are effected by my invention as will be apparent from the following description and claims taken in connection with the accompanying drawings, forming a part of this application, in which:

Fig. 1 is a horizontal sectional view taken along the line I-I of Fig. 3, looking in the direction of the arrows;

Fig. 2 is a longitudinal vertical sectional View taken along the line 11-11 of Fig. 3, lookingin the direction of the arrows; and- Fig. 3 is a transverse vertical sectional view taken along the line III-III of Fig. 2, looking in the direction of the arrows.

Referring now to the drawings, there is shown, at III, a furnace including front and rear walls I I and I2, respectively, and side walls l3. Positloned intermediate, and parallel to the side walls l3 at the bottom of the furnace. are a pair of parallel spaced supporting walls M (Fig, 3), each wall M, in conjunction with its adjacent furnace wall I3, defining a longitudinally-extending channel l5 for the reception of the ash conveying mechanism.

A pair of horizontally disposed, parallel and spaced structural members ll extend from front to rear of the furnace with their terminal portions supported by the front and rear walls of the furnace. A supporting plate structure I8 is disposed on the structural members I! and extends from front to rear of the furnace. Preferably, the supporting plate structure is formed of a plurality of sections, permitting ease of replacement in the event of wear or injury.

A pair of hollow elongated members 22 of inverted U-shape in cross section, are positioned on the supporting plate for reciprocating movement. The members 22are comprised by vertical side walls 23 and 24 connected by an arcuate top Wall 25, the latter having tuyre openings 26. The elongated members extend from front to rear of the furnace with the inner adjacent side walls 23 in spaced parallel relation and defining therebetween a retort 23a.

Preferably, the elongated members are comprised by a plurality of tapered intermediate sections 28 and straight terminal sections 29 and 30 (Fig. 2). The intermediate sections 28 taper both in width and in height from the front to the rear of the furnace, the outer surfaces of the sections of each member being in alignment to form a smooth wedge-like structure. The rear terminal section 29 and the forward terminal section 39 are of uniform width and height and serve as slides fitting the guide sleeves 3| and 32, respectively. The sections making each elongated member are retained in associated relation by being bolted, or otherwise secured, to an elongated bar 34 contiguous to the inner surface of the inner Wall 23 (Fig. 3)

The supporting plate structure It is provided at its longitudinal edges with an outwardly projecting rib or lip 35, which serves to support the inner edges of the longitudinal series of grates 35 whose outer ends are carried by the walls I4.

The vertical walls l4 and the front and rear furnace walls H and i2, together with the supporting plate structure l8 and the grates 35, define a plenum chamber 31 to which air under pressure is supplied from any suitable external source such as the blower 31a.

Openings 38 in the supporting plate structure [8 provide for the passage of air from the plenum chamber to the hollow interiors of the elongated members 22 and thence through the tuyre openings 25 to the fuel bed for aiding combustion thereof. Also, the grates 36 have tuyre openings 39 for supplying air from the plenum chamher to the fuel bed overlying the grates.

A ram cylinder 4| extends through the front wall H and is aligned with the retort. The cylstructure 6 i.

inder is supplied with fuel from the hopper 42 and the ram 43 expels fuel from the cylinder into the retort and feeds the fuel along the latter. The ram 43 is operated by means of a connecting rod 44 actuated from any suitable source of power, for example, the power cylinder Q5.

The elongated members 22 are reciprocated through an interconnection with the main fuel feeding ram 43. To this end, the elongated members are provided at their front ends with rods 41 projecting forwardly through the front wall of the furnace and slidably received in openings 48 in a cross-head 49 carried by the ram 53. Spaced nuts 50 and carried by the rods forwardly and rearwardly of the cross-head provide for adjustable lost motion of the elongated members relatively to the ram. 7

While under some operating conditions the main ram 43 may be sufficient to cause travel of the fuel longitudinally of the retort 23o, it is preferred to provide additional means for this purpose. To this end, wedges 53 having rearwardly directed faces 54, are bolted, or otherwise secured, to the vertical side walls 23 of the elongated members 22 Within the retort 23a, whereby, upon reciprocation of the elongated members, the fuel will be urged rearwardly along the retort,

The rearward taper of the elongated members 22 with respect to' the. vertical dimension tends to agitate the fuel in the retort 23a and force it outwardly over the sides of the latter, while the taper of the elongated members with respect to the transverse dimension agitates the fuel on the laterally extending grates and wedges it towards the sides of the furnace.

' Within the channels It are ash receiving troughs 59, each formed by the adjacent parallel walls l3 and I4 and by an inclined bottom structure 6!! extending longitudinally of the furnace with its rear terminal portion supported by the rear wall I2 of the furnace and with its forward terminal portion supported by the vertical plate Preferably, the trough bottom 60 is made up of a plurality of sections 52 having terminalflanges 63 connected-in any suitable manner, as by bolting.

The troughs 59 are inclined from the rear to the front of the furnace so that their front ends may discharge into ash pits 64, from which the refuse may be removed through openings 65, the openings being normally closed bydoors 56 hinged, at 67, to a portion 68 of the furnace front wall structure. These vertical portions 68 are provided with side wall portions 69 extending rearwardly at right angles thereto and forming supports for bearings ll] of the horizontal shaft H, which extends transversely of the furnace'and whose purpose will be hereinafter described.

Ash discharged from the grates 38 is received in the troughs 59 and moved therealong to the ash pits 64 by the conveying mechanisms l5, each comprised by a longitudinally-extending bar in resting upon the bottom of its trough and having its forward end supported in a bearing Ti inthe vertical wall plate 58, with its rear end guided by the bearing 18 at the rear of the furnace. A plurality of transversely-extendingv rams 79 are secured to the bar iii at intervals therealong by suitable means, such as the bolts 80. These rams are provided with upright front faces 8! and upper faces Bid sloping rearwardly therefrom, whereby, upon reciprocation of the the outer ends of the conveyor rods it.

rod 76, ash or other refuse is moved forwardly alon the trough 59 to the pit 54.

Reciprocatory movement of the ash conveying mechanisms is provided by interconnection thereof with the main fuel-feeding ram 4-3, and, to this end, the latter is provided with a depending lug 82 movable on the rod 83 between the adjustable abutmentst i. The rod is pivotally connected to the crank 85 carried by the shaft ll having cranks B3 pivotally connected to By suitable adjustment of the abutments 84, the extent of reciprocation of the rod 83, and, hence, of the conveyors may be varied relatively to that of the main ram.

In order to prevent burning or other injury to the plates Si forming the bottom of the ash receiving troughs, a water connection 93, having transverseperforated arms 94 is provided at the rear of each of the ash conveyors, these connections providing suflicient water to moisten the ash and thereby prevent burning of the conveyor structure.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited but is susceptible of various changes and modifications without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth inthe appended claims.

What I claim is:

1. Incombustion apparatus, a furnace having lateral ash discharge means, a horizontalfuel support, a pair of elongated members reciprocatorily mounted on said support'in spaced par allel relation and defining a retort extending from front to rear of the furnace, horizontal grates extending laterally from the elongated members to the ash-discharge means, mechanism for supplying fuel to the retort and feeding it longitudinally thereof, and means for reciprocating the elongated members, said members being tapered towards the rear, whereby reciprocatory movement thereof urges the fuel along the grates laterally of the furnace to the ash-discharge means.

2. In combustion apparatus, a retort comprised by plate structure having a supporting surface and a pair of elongated members reciprocatorily mounted on said supporting surface, feeding mechanism for supplying fuel to the retort, means providing for reciprocation of the elongated members, and grates extending laterally from said elongated members, each of said elongated members being comprised by a plurality of rearwardly tapered sections arranged in end-to-end relation with their outer surfaces in alignment with the surfaces of adjacent portions to form a continuous wedge, whereby reciprocatory movement thereof urges the fuel from the retort to and along the laterally extending grates.

3. In combustion apparatus, a retort comprised by plate structure having a supporting surface and a pair of elongated members reciprocatorily mounted on said supporting surface, feeding mechanism for supplying fuel to the retort, means providing for reciprocation of the elongated members, and grates extending laterally from said elongated members, said elongated members being rearwardly tapered with respect to the vertical dimension whereby upon reciprocation they will tend to raise the fuel bed and feed it from the retort to and along the laterally extending grates.

' 4. In combustion apparatus, a retort comprised by plate structure having a substantially horizontal supporting surface and a pair of elongated members reciprocatorily mounted on said supporting surface with their adjacent sides in parallel spaced relation; feeding mechanism for supplying fuel to the retort; means providing for reciprocation of the elongated members; and substantially horizontal grates extending laterally from said elongated members; each of said members being rearwardly tapered with respect to the transverse dimension, whereby upon reciprocation they will wedge the fuel bed along the laterally extending grates.

5. In combustion apparatus; a single retort comprised by plate structure having a substantially horizontal supporting surface and a pair of elongated members reciprocatorily mounted on said supporting surface with their adjacent sides in parallel spaced relation; feeding mechanism for supplying fuel to the retort; means providing for reciprocation of the elongated members; and substantially horizontal grates extending laterally from said elongated members, each of said members being rearwardly tapered with respect to the vertical and transverse dimensions, whereby upon reciprocation they will tend to raise the fuel bed and wedge it along the laterally extending grates.

6. In combustion apparatus; a furnace; means providing a substantially horizontal supporting surface extending between the front and rear walls thereof and disposed centrally transversely of the furnace; a pair of elongated members mounted on said supporting surface with their adjacent sides in spaced parallel relation and defining a retort extending from the front to the rear of the furnace; feeding mechanism for supplying fuel to the retort; substantially horizontal grates extending laterally from the elongated members towards the side walls of the furnace; and means providing for reciprocation of the elongated members, said last-mentioned means including driving connections between the feeding mechanism and said elongated members, said members being tapered longitudinally in width whereby reciprocatory movement thereof forces the fuel along the grates in directions transversely of the furnace.

7. A structure as specified in claim 6, wherein the driving connections between the feeding mechanism and the elongated members are of the lost-motion type.

8. A structure as specified in claim 6, wherein the feeding mechanism includes ram structure; and the driving connections between said feeding mechanism and the elongated members include laterally-extending arms carried by said ram structure, connecting rods secured at one end to the forward ends of the elongated members and having their other ends extending slidably through openings in the laterallyextending arms, and longitudinally adjustable stop members on said rods at both sides of said arms providing lost-motion driving connections.

9. In combustion apparatus, a furnace having front, rear and side walls; mean-s providing a substantially horizontal supporting surface between the front and rear walls; a pair of hollow elongated members reciprocatorily mounted on said supporting surface with their adjacent sides in spaced parallel relation and defining a retort extending from the front to the rear wall; mechanism for supplying'fuel to the retort; substantially horizontal grates extending laterally from the elongated members towards the side walls of the furnace; means providing for reciprocation of the elongated members; and means for supplying air under pressure to the hollow interiors of said members; said members having tuyere openings for passage of the air from their interiors to the fuel bed and being tapered from front to rear in width and in height, whereby, upon reciprocation, they tend to raise the fuel and force it laterally along the grates towards the furnace side walls.

10. A structure as specified in claim 9, wherein a plurality of forwardly-tapered wedges are secured to the adjacent sides of the elongated members defining the inner sides of the retort to aid in feeding the fuel longitudinally of said retort.

11. In combustion apparatus, a retort comprised by structure providing a substantially horizontal supporting surface and a pair of elongated members reciprocally mounted on said supporting surface with their adjacent sides in parallel spaced relation; feeding mechanism for supplying fuel to the retort; means providing for reciprocation of the elongated members; substantially horizontal grates extending laterally from said elongated members; and wedges carried by the inner adjacent side walls of said elongated members for moving the fuel longitudinally of the retort upon reciprocation of said members; each of said elongated members tapering towards the rear of said retort, whereby, upon reciprocation, said elongated members urge the fuel along the laterally extending grates.

12. In combustion apparatus; a retort comprised by a substantially horizontal fuel support and a pair of hollow elongated members reciprocatorily mounted on said support with the adjacent sides in parallel spaced relation; feeding mechanism for supplying fuel to the retort; means providing for reciprocation of the elongated members; substantially horizontal grates extending laterally from said elongated members; each of said members being comprised by spaced converging inner and outer side walls joined by an arcuate top wall having tuyre openings; said converging side walls providing for wedging action by the members upon reciprocation in order to force fuel laterally along the grates; and means providing for supply of air under pressure to the hollow interiors of the elongated members for emission through the tuyre openings to the overlying fuel bed.

13. For use in a single-retort stoker of the type wherein a pair of hollow elongated, longitudinally-tapered members are reciprocatorily mounted on a fuel support in parallel spaced relation, with the space therebetween said sides forming a retort from which fuel is adapted to be fed laterally along said fuel support by the wedging action of said longitudinally-tapered members upon reciprocation of the latter; a tuyere element adapted to comprise a section of one of said members and comprised by spaced vertical side walls and a top wall connecting the side walls, said side walls converging longitudinally.

14. For use in a single-retort stoker of the type wherein a pair of hollow, elongated, longitudinally-tapered members are reciprocatorily mounted on a fuel support with their adjacent sides in parallel spaced relation, with the space between said sides forming a retort from which fuel is adapted to be fed laterally along said fuel support by the wedging action of said longitudinally-tapered members upon reciprocation of the latter; a tuyere element of inverted U-shape in cross-section adapted to comprise a section of one of said members and comprising spaced vertical side walls having straight bottom edges, and an arcuate top wall connecting the side walls, said side walls converging longitudinally and terminating in parallel end planes perpendicular to one of said side walls, and. said top wall being inclined longitudinally with respect to the bottom edges of the side walls in the same direction as that in which the side walls converge.

DONALD J. MOSSHART. 

